> Computers (=RISC) are not microprogrammable, because it is slow; instead
>one relies on better compilers.
The microprogram is usually stored in a very fast RAM. Now let us have a look at a
modern
RISC architecture: it has a very fast RAM, namely the on-chip first level cache.
What is the difference of executing a microprogram consisting of simple instructions,
one of them at every clock cycle and the execution of a RISC program from the
instruction cache -- none !
Thus we still have microprogrammable machines, but the microprogram changes
dynamically.
When I heared a course on computer algebra I learned that a nearly optimal
hardware structure for solving group related problems like coxeter-todd coset
enumeration
is very similar to a modern RISC microprocessor.
I guess that an intensive investigation of hardware support for functional programmed
systems
will show that there is very little that could be added in hardware. And that this
little
thing does not yield very much.
Remember the fifth generation project. Japanese scientists developed a prolog engine.
In the same time a french enterprise developed a prolog compiler for the good old
68000.
Guess which system was faster, and which system was cheaper.
The versatility of modern architectures allows the application of complex and fast
algorithms (e.g. for garbage collection). In hardware one normally applies more simple
algorithms which can be executed faster. It turned out that in many cases the better
algorithms made it.
Just my opinion.
Andreas
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Andreas Doering
Medizinische Universitaet zu Luebeck
Institut fuer Technische Informatik
Email: [EMAIL PROTECTED]
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